According to the following site, Echo is based on Echo, Utah and the surrounding area. https://echoproject.fandom.com/wiki/Echo_(Town)
As for my belief that the Pueblo mentioned refers to Pueblo, Colorado -- Colorado is near Utah and Chase certainly could have gone to college in Colorado.
And remember -- TJ went to a Christian university named "CCU" -- and there is a college named Colorado Christian University. So, I believe Chase, Jenna, TJ and Carl went to college in Colorado.